gpu: nvgpu: add vidmem allocation ioctl

Add NVGPU_GPU_IOCTL_ALLOC_VIDMEM to the ctrl fd for letting userspace
allocate on-board GPU memory (aka vidmem).  The allocations are returned
as dmabuf fds.

Also, report the amount of local video memory in the gpu
characteristics.

Jira DNVGPU-19
Jira DNVGPU-38

Change-Id: I28e361d31bb630b96d06bb1c86d022d91c7592bc
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1181152
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
index 3e34b6b8..6b832670 100644
--- a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
@@ -704,6 +704,49 @@ clean_up:
         return err;
 }
 
+static int nvgpu_gpu_alloc_vidmem(struct gk20a *g,
+                        struct nvgpu_gpu_alloc_vidmem_args *args)
+{
+        u32 align = args->in.alignment ? args->in.alignment : SZ_4K;
+        int fd;
+
+        gk20a_dbg_fn("");
+
+        /* not yet supported */
+        if (WARN_ON(args->in.flags & NVGPU_GPU_ALLOC_VIDMEM_FLAG_CPU_MASK))
+                return -EINVAL;
+
+        /* not yet supported */
+        if (WARN_ON(args->in.flags & NVGPU_GPU_ALLOC_VIDMEM_FLAG_VPR))
+                return -EINVAL;
+
+        if (args->in.size & (SZ_4K - 1))
+                return -EINVAL;
+
+        if (!args->in.size)
+                return -EINVAL;
+
+        if (align & (align - 1))
+                return -EINVAL;
+
+        if (align > roundup_pow_of_two(args->in.size)) {
+                /* log this special case, buddy allocator detail */
+                gk20a_warn(dev_from_gk20a(g),
+                        "alignment larger than buffer size rounded up to power of 2 is not supported");
+                return -EINVAL;
+        }
+
+        fd = gk20a_vidmem_buf_alloc(g, args->in.size);
+        if (fd < 0)
+                return fd;
+
+        args->out.dmabuf_fd = fd;
+
+        gk20a_dbg_fn("done, fd=%d", fd);
+
+        return 0;
+}
+
 long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
         struct device *dev = filp->private_data;
@@ -951,6 +994,11 @@ long gk20a_ctrl_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg
                         (struct nvgpu_gpu_get_engine_info_args *)buf);
                 break;
 
+        case NVGPU_GPU_IOCTL_ALLOC_VIDMEM:
+                err = nvgpu_gpu_alloc_vidmem(g,
+                        (struct nvgpu_gpu_alloc_vidmem_args *)buf);
+                break;
+
         default:
                 dev_dbg(dev_from_gk20a(g), "unrecognized gpu ioctl cmd: 0x%x", cmd);
                 err = -ENOTTY;